The present invention relates to dynamic quality factor (Q) tuning without changing the antenna matching network in an electronic device, and more particularly, to a method for controlling an antenna network quality factor of a near field communication (NFC) device, and to an associated apparatus.
According to the related art, a conventional NFC device can be designed to communicate using a predetermined data rate, where it is typically needed to make sure of a proper value of the antenna network quality factor (or the so-called Q) in a design phase of the conventional NFC device. Tuning the antenna network quality factor to be smaller (e.g. a low Q) is needed for high data rate communication, while tuning the antenna network quality factor to be greater (e.g. a high Q) is preferred for low data rate communication. In a situation where the conventional NFC device should be capable of communicating using different data rates, respectively, quality factor tuning (or Q-tuning) is required. However, some problems may occur. For example, the antenna matching network of the conventional NFC device is typically equipped with additional components on a printed circuit board (PCB) of the conventional NFC device for setting a fixed Q value to make the conventional NFC device be suitable for communicating using different data rates, respectively. As a result, the tradeoff between the size of the conventional NFC device and the capability of respectively communicating using different data rates is typically introduced, since the size of the conventional NFC device corresponds to the total amount of components on the PCB. In another example, although the antenna matching network can be carefully designed by developers in the design phase of the conventional NFC device, because of the fixed characteristics of the additional components, the tradeoff between the performance of high data rate communication and the performance of low data rate communication is typically introduced. More particularly, in order to provide the conventional NFC device with the capability of operating in the absence of battery power through harvesting energy from the incoming field, tuning the antenna network quality factor to be greater (e.g. a high Q) is also needed. Although the matching network can be carefully designed by developers in the design phase of the conventional NFC device, because of the fixed characteristics of the additional components, the tradeoff between the performance of high data rate communication (which may be performed in a situation where the battery power is available) and the efficiency of harvesting energy from the incoming field is typically introduced. Thus, a novel method is required for improving the data transmission performance of all data rates of the NFC device at the same time.